North America Distribution

Facts About

Dwarf birch is a shrub up to 9 feet (3 m) tall, which inhabits ravines and plateaus of the alpine regions of Vermont, Maine, and New Hampshire. It is listed as rare in the latter two states. Its dark brown branches are hairless or with a few soft hairs, but some plants are intermediate in character between B. glandulosa and B. cordifolia, two species with which it overlaps in range and habitats. This shrub blooms in June-July in Maine.

Habitat

Alpine or subalpine zones, mountain summits and plateaus

Characteristics

Habitat

terrestrial

New England state

Maine

New Hampshire

Growth form

the plant is a shrub (a woody plant with several stems growing from the base)

Leaf type

the leaf blade is simple (lobed or unlobed but not separated into leaflets)

Leaves per node

there is one leaf per node along the stem

Leaf blade edges

the edge of the leaf blade has teeth

Leaf duration

the leaves drop off in winter (or they wither but persist on the plant)

armature on plant

the plant does not have spines, prickles, or thorns

Leaf blade length

15–60 mm

Leaf blade width

15–50 mm

Leaf stalk

the leaves have leaf stalks

Fruit type (general)

the fruit is dry but does not split open when ripe

Bark texture

the bark of an adult plant is thin and smooth

Twig winter color

brown

red

Bud scale number

there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed

Synonyms

Family

Genus

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Information from Dichotomous Key of Flora Novae Angliae

5. Betula minor
(Tuckerman) Fern.
NC

dwarf birch.
Betula papyracea Ait. var.
minor Tuckerman;
B. pubescens Ehrh. ssp.
minor (Tuckerman) A. & D. Löve;
B. saxophila Lepage
•
ME,
NH, vt. Alpine plateaus, slopes, gullies, and ravines. This species is sometimes often considered to be a hybrid-derived species of
Betula cordifolia and
B. glandulosa, given that it is intermediate in morphology and occurs where those species are sympatric. There may be two taxa involved here. One is characterized by glabrous branchlets and leaf blades and samaras 2.5–5 mm wide with individual wings wider than achene body (
B. minor s.s.). The other
is characterized by pubescent young branchlets and leaf blades and samaras 2–3.5 mm wide with individual wings up to as wide as the achene body (
B. borealis Spach
sensu Fernald 1950b; but this name misapplied as it consists of material of
B. pumila). I am tentatively following Furlow (1997) in treating
B. minor as a single, variable taxon.